Notes 1: Programming Languages

• What is programming?
  • Making a computer do what you want
  • Planning logical steps for a computer to perform in order to achieve a goal
  • Precisely entering commands
• A Hierarchy of Languages
  • Interpreted Languages (Python)
  • Compiled languages (C / C++)
  • Assembler Language
  • Binary / Machine Code (0001101010110)
• Binary “Hello World” (?)
  • 100101010010101001011101010110
    10010100100101010010010110011110
    01100101001111010111010101001010
    11101110111010101001010001000100
    10100100100011001001100101010111
    01101010100101010111100001010100
    00110101000101010001100110011001
    10010101001010100101110101011010
    10010010101001001011001111001100
    10011110101110101010010101110111
    
• X86 Assembly “Hello World”
  • title Hello World Program (hello.asm)
  • ; This program displays "Hello, World!" dosseg
  • .model small
  • .stack 100h .data
  • hello_message db 'Hello, World!',0dh,0ah,'$' .code
  • main proc
  • mov ax,@data
  • mov ds,ax mov ah,9
  • mov dx,offset hello_message
  • int 21h mov ax,4C00h
  • int 21h
  • main endp
  • end main
• C++ “Hello World”
  • #include <iostream.h>
  • main()
  • {
  • cout << "Hello World! ";
  • }
  • return 0
• Python “Hello World!”
  • print "Hello World"
• Specialized Languages
  • HTML, JavaScript
    • Creating pages readable by a web browser
  • SQL
    • Creating and manipulating information in a database
• A Few Computer Languages
  • ABC, Ada, ASP, Awk, BASIC, C, C++, C#, Caml, Cobol, Corba, Delphi, Eiffel, Erlang, Fortran, Haskell, Java, JavaScript, Lisp, Logo, Machine Code, Modula, Modula 2, Mozart, Mumps, Oberon, Objective C, Oz, Pascal, Perl, PHP, Pico, Python, Realbasic, Rebol, Rexx, RPG, Ruby, Scheme, Smalltalk, SQL, Squeak, TCL, Visual Basic